Output HTML markup can be improved

Consider the following additions:

<img> tag

• should be included image dimensions (width and height) not only to speed up the rendering as also to be W3c compliant. If using media library items it can be pulled with wp_get_attachment_metadata().
• Should be included a css class option to allow customization or images lazy loading plugin integration.
• Should be included alt parameter, this is important for SEO.

<a> tag

• Should be included title parameter.
• Should be included rel parameter for lightbox, colorbox, prettyPhoto, etc. integration.

None of these additions are expected to generate conflicts with owl-carousel.js code, I’ve made myself these changes and it works great.

I guess, in the simpliest way it would be enough to add some more options both at carousel custom post type and carousel $atts shortcodes and likewise improve the returned html.

You may take a look at this image carousel for an idea.

https://www.ads-software.com/plugins/carousel-slider/